‘Construction sets’, ‘construction kits’, or ‘building sets’ are playthings consisting of blocks or other modular elements aimed at constructing structures such as houses, bridges, or cranes. They originate from the world of engineering and machinery. Adults who created them were inspired by the architectural and technological environment and devised toys on the basis of the opportunities these environments afford for play and for pleasurable instruction. They belong to technology-inspired playthings, ‘technical toys’, appropriate in a world of increasing mechanisation, where the impact of engineering on society was increasingly visible and powerfully felt in everyday life. Technical toys however do not constitute a uniform category, but can be subdivided into numerous subsections as diverse as construction sets and toy trains – and more recently experiment kits and computer games, to name just a few.